Oil furnaces are expensive to maintain because of the high cost of oil. The U.S. Energy Information Administration claims that households spent an average of $2,558 from 2012 to 2013 on maintaining an oil furnace. Maintaining a gas furnace in the same period was $690.
There are pros and cons to using oil heat for a home. Though oil provides more British thermal units than other heating options, oil must be delivered to the home and kept in a tank on the property. Oil furnaces are usually easy to care for by the oil provider and cost less than other types of furnaces.
Typically, the maintenance associated with an oil furnace is more intense as the furnace collects a lot of soot and dirt, and oil filters must be changed often. Oil furnaces are also less efficient than other types of furnaces. Efficiency for furnaces is measured by a statistic known as the Annual Fuel Utilization Efficiency. For oil furnaces, this number typically ranges between 80 and 90 percent. However, when compared with a gas furnace, the gas efficiency is between 89 and 98 percent. However, it is important to keep in mind that any new furnace, whether oil or gas, is certainly going to be more efficient than the one that is being replaced.